Fuel control valve



4, 1964 (3.1. TERRY 3,

FUEL CONTROL VALVE Filed Jan. 2, 1963 272 INYENTOR.

United States Patent 3,143,126 FUEL CGNTROL VALVE Charles M. Terry, Decatur, Ill, assignor to A. W. Cash Valve Manufacturing Corporation, a corporation of Illinois Filed Jan. 2, 1963, Ser. No. 249,073 9 Claims. (Cl. 13794) This invention relates to a fuel control valve and more specifically to a thermostatically operated fuel control valve for use as a high temperature control on gas fired hot water heaters.

One form of the invention is embodied in a fuel control valve comprising a valve casing having an inlet and an outlet with an annular valve seat therebetween. A valve stem is mounted in the casing for movement between an upper cocked position and a lower uncooked position, the valve being open when the stem is in its upper position and closed when the stem is in its lower position. The stem has a downwardly facing shoulder on its lower portion and a transversely extending closure disc spaced above the shoulder for selectively engaging the valve seat. Associated with the closure disc is a spring member normally urging the closure disc toward the valve seat. The stem shoulder is selectively engaged by a bushing that releasably retains the stem in an out-ofline or upper cocked position to maintain the closure disc off the valve seat. The valve has means for releasing the stem from its cocked position including a temperature responsive power element and a stem guide actuated by said element to engage the lower tapered end of the stern. A spring force, which is overcome when the temperature responsive power element expands upon reaching a predetermined temperature, normally urges the stem guide away from the valve stem.

An object of this invention is to provide a new and improved fuel control valve.

Another object of the present invention is to provide a fuel control valve that can be manually reset to re-establish fuel fiow after the valve has been thermostatically closed.

Another object of this invention is to provide a thermostatically operated fuel control valve in which the temperature responsive power element is in in-line relationship with the valve so that the push action of the power element is used directly to close the valve without requiring any intermediate linkages with pivoted members resulting in a simpler construction than is now known in the art.

Further objects and advantaga will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is an elevational view of the valve mounted on a hot water tank with part of the valve casing broken away; and

FIGURE 2 is an enlarged vertical central sectional view showing the valve stem in open position in solid lines and in closed position in broken lines.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail an embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring to the drawings wherein a preferred form of the invention is illustrated, the reference character 10 generally designates a valve positioned on a hot water tank 11. The valve has a casing 12 providing an inlet port 13 and an outlet port 14. A valve seat 16 having a vertical axis separates the fuel passageway 18 into two chambers and as seen in FIGURE 2 the intake chamber 26 extends above the outlet chamber 22.

The valve casing 10 has a cap 24 which is threaded into its upper portion and which is sealed by a sealing ring 26. Cap 24 has an opening 28 which loosely engages a valve stem 36. The opening 28, which has a diameter slightly greater than that of the stem 3%, carries an 0-ring 32 of resilient material for forming a gas-tight seal around the valve stem. The O-ring is held in place by a rigid annular backing ring 34. O-ring 32 also acts as a pivot for the valve stem which is mounted for movement between an upper cocked position, as shown in solid lines in FIGURE 2, and a lower uncooked position, shown in broken lines.

The valve stem 30 has a transversely extending closure plate 36 forming a valve member which is selectively engageable with the valve seat 16 for opening and closing the valve. A helical valve spring 38, having its upper end abutting against the annular backing ring 34-, normally urges the closure plate 36 toward the valve seat 16.

A downwardly facing shoulder 37 is turned on the lower portion of the stem 39 and is selectively engaged by a release bushing 40 for releasably retaining the stem 36 in out-of-line cocked position to maintain the closure plate 36 off the valve seat 16. The lower portion of the valve stem is received in a cylindrical bore 3% in the release bushing 40.

The valve has means for releasing the stem from its upper cocked position including a temperature responsive power element shown generally at 42. The power element is mounted below the valve casing by an elongate tube 43. A push rod 44 is mounted for movement in tube 43 and actuates astem guide or actuator 46 which, when moved into its upper position, shown in broken lines in FIGURE 2, releases the stem 30 from its cocked position thus enabling gravitational forces and valve spring 38 to seat the closure plate 36 against valve seat 16 whereby the valve is closed.

The illustrated form of the invention has a stem guide spring 48 which normally urges the stern guide or actuator 46 toward its lower position and also maintains the release bushing 40 in place.

The valve stem shown has a conical lower end 50 which is engaged by the beveled upper end 52 of the stem guide 46 to insure proper engagement of the stem 36 by guide or actuator 46 and to facilitate smooth operation of the valve. The stem guide has a central bore 54 for receiving the valve stem 3i when the valve is closed so that proper seating of the closure plate 36 on the valve seat 16 is obtained and a fuel-tight seal results.

The valve stem St) has an exposed end 56 for manually resetting the stem in cocked position to reestablish fuel flow through the valve.

In operation, fuel flows through the valve in the direction shown by the arrows in FIGURE 2 and then is piped down to the burners (not shown) of a hot water heater. The temperature responsive power element 42 senses the temperature of the water in approximately the top six inches of the water tank, and if the water should reach a temperature in excess of the thermostatic setting of the water heater, the temperature responsive element will expand against the push rod 44 which, in turn, comes in contact with the stern guide or actuator 46. The stem guide moves upward in such a manner as to engage the conical pointed end 50 of the valve stem 30 projecting into the release bushing 40. The engagement of the valve stem by the stem guide produces a centering effect uncocking the valve stem from the release bushing 40 and allowing the valve spring 38 to force the valve stem 38 assembly into a closed position, thereby shutting oif the gas flow.

With the gas shut off, the energy input is removed and there can be no further build-up of temperatures in the system until the temperature in the water heater has dropped down into a safe operating condition, When the temperature does return to normal, the stem guide spring 48 will force the push rod 44 against the piston of the thermal element, sending it back to its open position where it will remain until subjected to high temperatures again.

When this occurs, the valve stem assembly can be manually re-opened, thus re-establishing gas flow and making it possible to light the heater on the presumption that whatever caused the heater to be overheated in the first place has now been corrected. If the presumption is incorrect, the heater will again overheat and the energy shut-off will go through the same cycle as before, thereby protecting the homeowner from a dangerous high temperature condition ever being developed.

I claim:

1. A thermostatically operated fuel control valve, comprising: a valve casing providing an inlet port and an outlet port; a valve seat between said inlet and outlet port symmetric about a centerline; a valve stem pivotally and slidably mounted in said casing for movement between an upper cocked position spaced from said centerline and a lower position concentric about said centerline, said valve being open when said stem is in said upper cocked position and being closed when said stem is in said lower position; said valve stem having a downwardly facing shoulder spaced from the lower end of said stem and a transversely extending closure plate spaced above said shoulder for selectively engaging said valve seat; spring means normally biasing said closure plate toward said valve seat; a release bushing selectively engaging the shoulder of said stem for releasably retaining the stem in said cocked position to maintain said closure plate separated from said valve seat; and temperature responsive means normally spaced from said lower end for moving said stem from said out-of-line position whereby the valve closes.

2. The thermostatically operated fuel control valve, as specified in claim 1 in which the valve stem has an exposed end for manually resetting the stem in cocked position to re-establish fuel fiow after the valve has been closed.

3. The thermostatically operated fuel control valve as specified in claim 1 in which the valve stem has a tapered portion at one end and in which the temperature position and being closed when said stem is in said lower uncooked position, said stem having a shoulder turned thereon and a transversely extending closure disc spaced above said shoulder for seating against said valve seat; a first spring member normally urging said disc toward said valve seat; a release bushing engageable with said shoulder for releasably retaining the stem in said upper cocked position for maintaining said closure disc olf said valve seat; and means for releasing said stem from said upper cocked position including a temperature responsive element and a stem guide normally spaced from the lower end of said stem actuated by said element for engaging the stem to move it to said uncooked position; and a second spring member normally urging said stem guide away from said stem.

5. A thermostatically operated fuel control valve comprising: a valve casing having an inlet port and an outlet port with a valve seat intermediate said inlet and outlet port; a valve stem mounted in said casing for movement between an open cocked position and a closed uncocked position, said stem having a shoulder and a transversely extending closure disc spaced from said shoulder for seating against said valve seat; a helical valve spring encircling said stem and normally urging responsibe means comprises a stem guide for selectively said disc toward said valve seat; a release bushing engageable with said shoulder for releasably retaining the stem in said cocked position for maintaining said closure disc ofi said valve seat, said bushing having a cylindrical bore therethrough for receiving a part of said valve stem extending beyond said shoulder; means for releasing said stem from said cocked position including a temperature responsive element, a push rod directly engageable by said element and mounted for longitudinal movement, and a stem guide having opposed ends and a central bore for receiving said valve stem part, said stern guide being mounted for upward movement within the cylindrical bore of said bushing to engage and laterally shift said valve stem for release of said shoulder from said bushing; and a stem guide spring urging the stem guide away from the stem.

6. A thermostatically operated fuel control valve as specified in claim 5 in which said valve seat, release bushing, stem guide, push rod and temperature responsive element are disposed with a common axis for utilizing the push action of the temperature responsive element directly to place the valve stem on said axis and close the valve.

7. A thermostatically operated fluid control valve, comprising: a valve casing having inlet and outlet ports with a valve seat intermediate said ports, said valve seat having a centerline; a valve stem having a valve member mounted between the ends thereof selectively engageable with said seat, said valve stem having a tapered portion at one end thereof; means urging the valve member toward said seat; means engageable with said stem for holding the stem in a cooked position spaced from said centerline to maintain the valve member off said seat; means responsive to temperature above a predetermined value for releasing said valve stem from the cocked position comprising a stem guide selectively engageable with said tapered portion for returning said valve stem to said centerline to uncock the stem thereby effecting valve closure.

8. A thermostatically operated control valve as defined in claim 7 in which said valve means engageable with the valve stem and said stem guide are symmetric about said centerline.

9. A thermostatically operated fuel control valve for shutting 01f fuel flow, comprising: a valve casing having an inlet and an outlet port with a valve seat intermediate said inlet and outlet ports having a centerline; a valve stem pivotally and slidably mounted in said casing for movement between an upper cocked position spaced from said centerline and a lower uncooked position concentric with said centerline, said stem having a closure plate thereon for selectively engaging said seat when said 55 stem is in the uncooked position, means for engaging said stem for holding the closure plate away from said seat and maintaining said stem in the uncooked position, and a temperature responsive actuator for centering said stem and closing said plate above a predetermined maximum temperature, said actuator being slidably mounted in said casing concentric to said centerline for recriproeating motion along said centerline whereby the fuel flow is shut off when the maximum temperature is exceeded.

References Cited in the file of this patent UNITED STATES PATENTS Spencer June 2, 1934 Burklin Nov. 3, 1942 Newell Feb. 28, 19 50 Butterfield Apr. 3, 1951 Drew Nov. 24, 1955 

7. A THERMOSTATICALLY OPERATED FLUID CONTROL VALVE, COMPRISING: A VALVE CASING HAVING INLET AND OUTLET PORTS WITH A VALVE SEAT INTERMEDIATE SAID PORTS, SAID VALVE SEAT HAVING A CENTERLINE; A VALVE STEM HAVING A VALVE MEMBER MOUNTED BETWEEN THE ENDS THEREOF SELECTIVELY ENGAGEABLE WITH SAID SEAT, SAID VALVE STEM HAVING A TAPERED PORTION AT ONE END THEREOF; MEANS URGING THE VALVE MEMBER TOWARD SAID SEAT; MEANS ENGAGEABLE WITH SAID STEM FOR HOLDING THE STEM IN A COCKED POSITION SPACED FROM SAID CENTERLINE TO MAINTAIN THE VALVE MEMBER OFF SAID SEAT; MEANS RESPONSIVE TO TEMPERATURE ABOVE A PREDETERMINED VALUE FOR RELEASING SAID VALVE STEM FROM THE COCKED POSITION COMPRISING A STEM GUIDE SELECTIVELY ENGAGEABLE WITH SAID TAPERED PORTION FOR RETURNING SAID VALVE STEM TO SAID CENTERLINE TO UNCOCK THE STEM THEREBY EFFECTING VALVE CLOSURE. 